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Finding the Fourth Proportional to 91.20, 136.60 and 60.72

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Solution

The fourth proportional to 91.20, 136.60 and 60.72 is: 90.95

Step by Step Solution

  1. Step 1: Write the proportion equation
    91.20 : 136.60 = 60.72 : x
  2. Step 2: Convert to fraction form
    91.20/136.60 = 60.72/x
  3. Step 3: Cross multiply
    91.20x = 136.60 × 60.72
  4. Step 4: Simplify right side
    91.20x = 8,294.35
  5. Step 5: Solve for x
    x = 8,294.35/91.20
  6. Step 6: Final answer
    x = 90.95

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.